1. Field of Art
The disclosure generally relates to the field of mobile computing devices and more particularly to identifying interaction with a touchscreen of a mobile computing device.
2. Description of Art
A growing number of devices, such as smart phones or tablet computers, use touch-sensitive screens, or “touchscreens,” as their primary input mechanism. Touchscreens may be constructed in a variety of ways, such as, pressure-sensitive (resistive), electrically sensitive (capacitive), acoustically sensitive (SAW or surface acoustic wave), photo-sensitive (infra-red), to receive information from a user. Most conventional touchscreen designs identify when an object, such as a user or a stylus, physically contacts a region of the touchscreen by comparing the signal intensity of different regions of the touchscreen to a threshold value. When the signal intensity of a region exceeds the threshold, the touchscreen determines that an object is physically touching that region.
However, relying solely on comparison of signal intensity to a threshold introduces inaccuracy into contact detection. For example, as an object moves towards the touchscreen or moves away from the touchscreen, the centroid of the object shifts, causing instability in the detection of physical contact with the touchscreen. Also, as the surface area of an object contacting the touchscreen changes, regions of the touchscreen where signal intensity changes, causing errors in identification of the region of the touchscreen being contacted. Additionally, in some touchscreen designs, external conditions, such as the presence of a screen covering or the surface on which the touchscreen rests, affects a baseline value of the touchscreen, introducing errors into the determination of when the signal intensity exceeds the threshold.
Additionally, conventional touchscreens are only able to determine when the touchscreen is physically contacted and do not provide any information about the intensity at which the touchscreen is contacted.